According to the different working principles, the conductivity meter can be divided into two types: the balance indicator and the direct reading type. In order to avoid the change of the concentration of the electrolyte solution due to the polarization effect, the conductivity meter needs to use the AC power supply.
The main technical characteristics of electrical conductivity meter and its verification method
1, display value error
Verification method: comparison measurement with standard AC resistance to determine the indication error
2, repeatability of electrometer
Verification method: similar to an electrometer reference error verification, repeated measurements at a certain value 3-5 times to repeat the repeatability of the repeated measurements
3, constant regulator error
Verification method: measuring the resistance value of the standard flow resistance with a conductivity meter and determining the error of the constant regulator of the conductivity meter
4, instrument reference error
Verification method: the conductance standard solution is used for matching measurement. If the conductivity cell constant is unknown, it is calibrated with a conductivity standard solution first, then the conductivity of another standard solution is measured again.
5. Repeatability of instrument measurement
Verification method: repeated measurements are carried out by a standard solution of electric conductance for 3-5 times, and repeatability is expressed by extreme difference